Almost there

Robert Goldman rpgoldman at
Wed Jul 15 00:34:01 UTC 2015

On 7/14/15 Jul 14 -6:04 PM, Attila Lendvai wrote:
>> I'm inclined to remove the export of *IMMUTABLE-SYSTEMS*.  It hasn't
>> been used in a released version of ASDF AFAIK, so it seems benign to
>> remove it.
> isn't that also the case for REGISTER-IMMUTABLE-SYSTEM?
> if that export sticks in the release then it'll be a headache down the
> road (assuming that it is indeed an unfortunate name and not just my
> lone opinion).

OK, I just had a look at rewriting REGISTER-IMMUTABLE-SYSTEM and it is
*not* amenable to a rewrite as a setf-able predicate.  There are all
kinds of side-effecting in that code that would have to be disentangled
to make the "query" form of that function work.

If anyone is interested in carrying this through, I'm attaching my
abortive version of find-system.lisp with the beginnings of a rewrite.

But it's way more than I want to do before 3.1.5 is released.

Attila, if you care enough, LMK when you think you could submit a patch.
 Otherwise we go with what we have (except I remove the export of


-------------- next part --------------
;;;; -------------------------------------------------------------------------
;;;; Finding systems

(uiop/package:define-package :asdf/find-system
  (:recycle :asdf/find-system :asdf)
  (:use :uiop/common-lisp :uiop :asdf/upgrade
    :asdf/cache :asdf/component :asdf/system)
   #:remove-entry-from-registry #:coerce-entry-to-directory
   #:coerce-name #:primary-system-name #:coerce-filename
   #:find-system #:locate-system #:load-asd
   #:system-registered-p #:register-system #:registered-systems #:clear-system #:map-systems
   #:missing-component #:missing-requires #:missing-parent
   #:formatted-system-definition-error #:format-control #:format-arguments #:sysdef-error
   #:load-system-definition-error #:error-name #:error-pathname #:error-condition
   #:*system-definition-search-functions* #:search-for-system-definition
   #:*central-registry* #:probe-asd #:sysdef-central-registry-search
   #:contrib-sysdef-search #:sysdef-find-asdf ;; backward compatibility symbols, functions removed
   #:sysdef-preloaded-system-search #:register-preloaded-system #:*preloaded-systems*
   #:register-immutable-system ; DEPRECATED
   ;; #:*immutable-systems* REMOVED
   #:*defined-systems* #:clear-defined-systems
   ;; defined in source-registry, but specially mentioned here:
   #:initialize-source-registry #:sysdef-source-registry-search))
(in-package :asdf/find-system)

(with-upgradability ()
  (declaim (ftype (function (&optional t) t) initialize-source-registry)) ; forward reference

  (define-condition missing-component (system-definition-error)
    ((requires :initform "(unnamed)" :reader missing-requires :initarg :requires)
     (parent :initform nil :reader missing-parent :initarg :parent)))

  (define-condition formatted-system-definition-error (system-definition-error)
    ((format-control :initarg :format-control :reader format-control)
     (format-arguments :initarg :format-arguments :reader format-arguments))
    (:report (lambda (c s)
               (apply 'format s (format-control c) (format-arguments c)))))

  (define-condition load-system-definition-error (system-definition-error)
    ((name :initarg :name :reader error-name)
     (pathname :initarg :pathname :reader error-pathname)
     (condition :initarg :condition :reader error-condition))
    (:report (lambda (c s)
               (format s (compatfmt "~@<Error while trying to load definition for system ~A from pathname ~A: ~3i~_~A~@:>")
                       (error-name c) (error-pathname c) (error-condition c)))))

  (defun sysdef-error (format &rest arguments)
    (error 'formatted-system-definition-error :format-control
           format :format-arguments arguments))

  (defun coerce-name (name)
    (typecase name
      (component (component-name name))
      (symbol (string-downcase (symbol-name name)))
      (string name)
      (t (sysdef-error (compatfmt "~@<Invalid component designator: ~3i~_~A~@:>") name))))

  (defun primary-system-name (name)
    ;; When a system name has slashes, the file with defsystem is named by
    ;; the first of the slash-separated components.
    (first (split-string (coerce-name name) :separator "/")))

  (defun coerce-filename (name)
    (frob-substrings (coerce-name name) '("/" ":" "\\") "--"))

  (defvar *defined-systems* (make-hash-table :test 'equal)
    "This is a hash table whose keys are strings, being the
names of the systems, and whose values are pairs, the first
element of which is a universal-time indicating when the
system definition was last updated, and the second element
of which is a system object.")

  (defun system-registered-p (name)
    (gethash (coerce-name name) *defined-systems*))

  (defun registered-systems ()
    (loop :for registered :being :the :hash-values :of *defined-systems*
          :collect (coerce-name (cdr registered))))

  (defun register-system (system)
    (check-type system system)
    (let ((name (component-name system)))
      (check-type name string)
      (asdf-message (compatfmt "~&~@<; ~@;Registering ~3i~_~A~@:>~%") system)
      (unless (eq system (cdr (gethash name *defined-systems*)))
        (setf (gethash name *defined-systems*)
              (cons (if-let (file (ignore-errors (system-source-file system)))
                      (get-file-stamp file))

  (defvar *preloaded-systems* (make-hash-table :test 'equal))

  (defun make-preloaded-system (name keys)
    (apply 'make-instance (getf keys :class 'system)
           :name name :source-file (getf keys :source-file)
           (remove-plist-keys '(:class :name :source-file) keys)))

  (defun sysdef-preloaded-system-search (requested)
    (let ((name (coerce-name requested)))
      (multiple-value-bind (keys foundp) (gethash name *preloaded-systems*)
        (when foundp
          (make-preloaded-system name keys)))))

  (defun register-preloaded-system (system-name &rest keys)
    (setf (gethash (coerce-name system-name) *preloaded-systems*) keys))

  (dolist (s '("asdf" "uiop" "asdf-driver" "asdf-defsystem" "asdf-package-system"))
    ;; don't bother with these, no one relies on them: "asdf-utils" "asdf-bundle"
    (register-preloaded-system s :version *asdf-version*))

  (defvar *immutable-systems* nil
    "An hash-set (equal hash-table mapping keys to T) of systems that are immutable,
i.e. already loaded in memory and not to be refreshed from the filesystem.
They will be treated specially by find-system, and passed as :force-not argument to make-plan.

If you deliver an image with many systems precompiled, *and* do not want to check the filesystem
for them every time a user loads an extension, what more risk a problematic upgrade or catastrophic
downgrade, before you dump an image, use:
   (setf asdf::*immutable-systems* (uiop:list-to-hash-set (asdf:already-loaded-systems)))")

  (defun sysdef-immutable-system-search (requested)
    (let ((name (coerce-name requested)))
      (when (and *immutable-systems* (gethash name *immutable-systems*))
        (or (cdr (system-registered-p requested))
            (sysdef-preloaded-system-search name)
            (error 'formatted-system-definition-error
                   :format-control "Requested system ~A is in the *immutable-systems* set, ~
but not loaded in memory"
                   :format-arguments (list name))))))

  (defun register-immutable-system (system-name &key (version t))
    "Deprecated method of registering a system as immutable. Preferred method is to use
\(setf (immutable-system-p system-name) t\)."
    (setf (immutable-system-p system-name :version version) t))

  (defun (setf immutable-system-p) (value system-name &key (version t))
    ;; we do not allow restoring a system's mutability.
    (unless (typep value '(eql t))
      (error 'type-error :datum value :expected-type '(eql t)))
    (let* ((system-name (coerce-name system-name))
           (registered-system (cdr (system-registered-p system-name)))
           (default-version? (eql version t))
           (version (cond ((and default-version? registered-system)
                           (component-version registered-system))
                          (default-version? nil)
                          (t version))))
      (unless registered-system
        (register-system (make-preloaded-system system-name (list :version version))))
      (register-preloaded-system system-name :version version)
      (unless *immutable-systems*
        (setf *immutable-systems* (list-to-hash-set nil)))
      (setf (gethash (coerce-name system-name) *immutable-systems*) t)))

  (defun immutable-system-p (system-name &key (version t))
    (let* ((system-name (coerce-name system-name))
           (registered-system (cdr (system-registered-p system-name)))
           (default-version? (eql version t))
           (processed-version (cond ((and default-version? registered-system)
                            (component-version registered-system))
                           (default-version? nil)
                           (t version))))
      (if registered-system
          (when (and version (not (eq version t)))
            (unless (equalp (component-version registered-system) version)
              ;; ugh: forward reference...
              (error 'missing-component-of-version :version version :requires system-name)))
          (register-system (make-preloaded-system system-name (list :version processed-version))))
      (register-preloaded-system system-name :version processed-version)
      (unless *immutable-systems*
        (setf *immutable-systems* (list-to-hash-set nil)))
      (gethash (coerce-name system-name) *immutable-systems*)))

  (defun clear-system (system)
    "Clear the entry for a SYSTEM in the database of systems previously loaded,
unless the system appears in the table of *IMMUTABLE-SYSTEMS*.
Note that this does NOT in any way cause the code of the system to be unloaded.
Returns T if cleared or already cleared,
NIL if not cleared because the system was found to be immutable."
    ;; There is no "unload" operation in Common Lisp, and
    ;; a general such operation cannot be portably written,
    ;; considering how much CL relies on side-effects to global data structures.
    (let ((name (coerce-name system)))
      (unless (and *immutable-systems* (gethash name *immutable-systems*))
        (remhash (coerce-name name) *defined-systems*)
        (unset-asdf-cache-entry `(locate-system ,name))
        (unset-asdf-cache-entry `(find-system ,name))

  (defun clear-defined-systems ()
    ;; Invalidate all systems but ASDF itself, if registered.
    (loop :for name :being :the :hash-keys :of *defined-systems*
          :unless (equal name "asdf") :do (clear-system name)))

  (register-hook-function '*post-upgrade-cleanup-hook* 'clear-defined-systems nil)

  (defun map-systems (fn)
    "Apply FN to each defined system.

FN should be a function of one argument. It will be
called with an object of type asdf:system."
    (loop :for registered :being :the :hash-values :of *defined-systems*
          :do (funcall fn (cdr registered)))))

;;; for the sake of keeping things reasonably neat, we adopt a
;;; convention that functions in this list are prefixed SYSDEF-
(with-upgradability ()
  (defvar *system-definition-search-functions* '())

  (defun cleanup-system-definition-search-functions ()
    (setf *system-definition-search-functions*
           ;; Remove known-incompatible sysdef functions from old versions of asdf.
           (remove-if #'(lambda (x) (member x '(contrib-sysdef-search sysdef-find-asdf sysdef-preloaded-system-search)))
           ;; Tuck our defaults at the end of the list if they were absent.
           ;; This is imperfect, in case they were removed on purpose,
           ;; but then it will be the responsibility of whoever does that
           ;; to upgrade asdf before he does such a thing rather than after.
           (remove-if #'(lambda (x) (member x *system-definition-search-functions*))

  (defun search-for-system-definition (system)
    (let ((name (coerce-name system)))
      (flet ((try (f) (if-let ((x (funcall f name))) (return-from search-for-system-definition x))))
        (try 'find-system-if-being-defined)
        (try 'sysdef-immutable-system-search)
        (map () #'try *system-definition-search-functions*)
        (try 'sysdef-preloaded-system-search))))

  (defvar *central-registry* nil
    "A list of 'system directory designators' ASDF uses to find systems.

A 'system directory designator' is a pathname or an expression
which evaluates to a pathname. For example:

    (setf asdf:*central-registry*
          (list '*default-pathname-defaults*

This is for backward compatibility.
Going forward, we recommend new users should be using the source-registry.

  (defun probe-asd (name defaults &key truename)
    (block nil
      (when (directory-pathname-p defaults)
        (if-let (file (probe-file*
                        (parse-unix-namestring name :type "asd")
                        #'(lambda () (ensure-absolute-pathname defaults 'get-pathname-defaults nil))
                       :truename truename))
          (return file))
        #-(or clisp genera) ; clisp doesn't need it, plain genera doesn't have read-sequence(!)
          (when (physical-pathname-p defaults)
            (let ((shortcut
                     :defaults defaults :case :local
                     :name (strcat name ".asd")
                     :type "lnk")))
              (when (probe-file* shortcut)
                (ensure-pathname (parse-windows-shortcut shortcut) :namestring :native)))))))))

  (defun sysdef-central-registry-search (system)
    (let ((name (primary-system-name system))
          (to-remove nil)
          (to-replace nil))
      (block nil
             (dolist (dir *central-registry*)
               (let ((defaults (eval dir))
                 (when defaults
                   (cond ((directory-pathname-p defaults)
                          (let* ((file (probe-asd name defaults :truename *resolve-symlinks*)))
                            (when file
                              (return file))))
                              (let* ((*print-circle* nil)
                                       (format nil
                                               (compatfmt "~@<While searching for system ~S: ~3i~_~S evaluated to ~S which is not an absolute directory.~@:>")
                                               system dir defaults)))
                                (error message))
                            (remove-entry-from-registry ()
                              :report "Remove entry from *central-registry* and continue"
                              (push dir to-remove))
                            (coerce-entry-to-directory ()
                              :test (lambda (c) (declare (ignore c))
                                      (and (not (directory-pathname-p defaults))
                                            (setf directorized
                                                  (ensure-directory-pathname defaults)))))
                              :report (lambda (s)
                                        (format s (compatfmt "~@<Coerce entry to ~a, replace ~a and continue.~@:>")
                                                directorized dir))
                              (push (cons dir directorized) to-replace))))))))
          ;; cleanup
          (dolist (dir to-remove)
            (setf *central-registry* (remove dir *central-registry*)))
          (dolist (pair to-replace)
            (let* ((current (car pair))
                   (new (cdr pair))
                   (position (position current *central-registry*)))
              (setf *central-registry*
                    (append (subseq *central-registry* 0 position)
                            (list new)
                            (subseq *central-registry* (1+ position))))))))))

  (defmethod find-system ((name null) &optional (error-p t))
    (when error-p
      (sysdef-error (compatfmt "~@<NIL is not a valid system name~@:>"))))

  (defmethod find-system (name &optional (error-p t))
    (find-system (coerce-name name) error-p))

  (defun find-system-if-being-defined (name)
    ;; notable side effect: mark the system as being defined, to avoid infinite loops
    (first (gethash `(find-system ,(coerce-name name)) *asdf-cache*)))

  (defun load-asd (pathname
                   &key name (external-format (encoding-external-format (detect-encoding pathname)))
                   &aux (readtable *readtable*) (print-pprint-dispatch *print-pprint-dispatch*))
    ;; Tries to load system definition with canonical NAME from PATHNAME.
    (with-asdf-cache ()
        (let ((*package* (find-package :asdf-user))
              ;; Note that our backward-compatible *readtable* is
              ;; a global readtable that gets globally side-effected. Ouch.
              ;; Same for the *print-pprint-dispatch* table.
              ;; We should do something about that for ASDF3 if possible, or else ASDF4.
              (*readtable* readtable)
              (*print-pprint-dispatch* print-pprint-dispatch)
              (*print-readably* nil)
                ;; resolve logical-pathnames so they won't wreak havoc in parsing namestrings.
                (pathname-directory-pathname (physicalize-pathname pathname))))
              ((error #'(lambda (condition)
                          (error 'load-system-definition-error
                                 :name name :pathname pathname
                                 :condition condition))))
            (asdf-message (compatfmt "~&~@<; ~@;Loading system definition~@[ for ~A~] from ~A~@:>~%")
                          name pathname)
            (load* pathname :external-format external-format))))))

  (defvar *old-asdf-systems* (make-hash-table :test 'equal))

  (defun check-not-old-asdf-system (name pathname)
    (or (not (equal name "asdf"))
        (null pathname)
        (let* ((version-pathname (subpathname pathname "version.lisp-expr"))
               (version (and (probe-file* version-pathname :truename nil)
                             (read-file-form version-pathname)))
               (old-version (asdf-version)))
            ((version< old-version version) t) ;; newer version: good!
            ((equal old-version version) nil) ;; same version: don't load, but don't warn
            (t ;; old version: bad
              (list (namestring pathname) version) *old-asdf-systems*
              #'(lambda ()
                 (let ((old-pathname
                         (if-let (pair (system-registered-p "asdf"))
                           (system-source-file (cdr pair)))))
                   (warn "~@<~
        You are using ASDF version ~A ~:[(probably from (require \"asdf\") ~
        or loaded by quicklisp)~;from ~:*~S~] and have an older version of ASDF ~
        ~:[(and older than 2.27 at that)~;~:*~A~] registered at ~S. ~
        Having an ASDF installed and registered is the normal way of configuring ASDF to upgrade itself, ~
        and having an old version registered is a configuration error. ~
        ASDF will ignore this configured system rather than downgrade itself. ~
        In the future, you may want to either: ~
        (a) upgrade this configured ASDF to a newer version, ~
        (b) install a newer ASDF and register it in front of the former in your configuration, or ~
        (c) uninstall or unregister this and any other old version of ASDF from your configuration. ~
        Note that the older ASDF might be registered implicitly through configuration inherited ~
        from your system installation, in which case you might have to specify ~
        :ignore-inherited-configuration in your in your ~~/.config/common-lisp/source-registry.conf ~
        or other source-registry configuration file, environment variable or lisp parameter. ~
        Indeed, a likely offender is an obsolete version of the cl-asdf debian or ubuntu package, ~
        that you might want to upgrade (if a recent enough version is available) ~
        or else remove altogether (since most implementations ship with a recent asdf); ~
        if you lack the system administration rights to upgrade or remove this package, ~
        then you might indeed want to either install and register a more recent version, ~
        or use :ignore-inherited-configuration to avoid registering the old one. ~
        Please consult ASDF documentation and/or experts.~@:>~%"
                         old-version old-pathname version pathname))))
             nil))))) ;; only issue the warning the first time, but always return nil

  (defun locate-system (name)
    "Given a system NAME designator, try to locate where to load the system from.
FOUNDP is true when a system was found,
either a new unregistered one or a previously registered one.
FOUND-SYSTEM when not null is a SYSTEM object that may be REGISTER-SYSTEM'ed.
PATHNAME when not null is a path from which to load the system,
either associated with FOUND-SYSTEM, or with the PREVIOUS system.
PREVIOUS when not null is a previously loaded SYSTEM object of same name.
PREVIOUS-TIME when not null is the time at which the PREVIOUS system was loaded."
    (let* ((name (coerce-name name))
           (in-memory (system-registered-p name)) ; load from disk if absent or newer on disk
           (previous (cdr in-memory))
           (previous (and (typep previous 'system) previous))
           (previous-time (car in-memory))
           (found (search-for-system-definition name))
           (found-system (and (typep found 'system) found))
           (pathname (ensure-pathname
                      (or (and (typep found '(or pathname string)) (pathname found))
                          (and found-system (system-source-file found-system))
                          (and previous (system-source-file previous)))
                      :want-absolute t :resolve-symlinks *resolve-symlinks*))
           (foundp (and (or found-system pathname previous) t)))
      (check-type found (or null pathname system))
      (unless (check-not-old-asdf-system name pathname)
          (previous (setf found nil pathname nil))
           (setf found (sysdef-preloaded-system-search "asdf"))
           (assert (typep found 'system))
           (setf found-system found pathname nil))))
      (values foundp found-system pathname previous previous-time)))

  (defmethod find-system ((name string) &optional (error-p t))
    (with-asdf-cache (:key `(find-system ,name))
      (let ((primary-name (primary-system-name name)))
        (unless (equal name primary-name)
          (find-system primary-name nil)))
      (or (and *immutable-systems* (gethash name *immutable-systems*)
               (or (cdr (system-registered-p name))
                   (sysdef-preloaded-system-search name)))
          (multiple-value-bind (foundp found-system pathname previous previous-time)
              (locate-system name)
            (assert (eq foundp (and (or found-system pathname previous) t)))
            (let ((previous-pathname (and previous (system-source-file previous)))
                  (system (or previous found-system)))
              (when (and found-system (not previous))
                (register-system found-system))
              (when (and system pathname)
                (setf (system-source-file system) pathname))
              (when (and pathname
                         (let ((stamp (get-file-stamp pathname)))
                           (and stamp
                                (not (and previous
                                          (or (pathname-equal pathname previous-pathname)
                                              (and pathname previous-pathname
                                                    (physicalize-pathname pathname)
                                                    (physicalize-pathname previous-pathname))))
                                          (stamp<= stamp previous-time))))))
                ;; only load when it's a pathname that is different or has newer content, and not an old asdf
                (load-asd pathname :name name)))
            (let ((in-memory (system-registered-p name))) ; try again after loading from disk if needed
                 (when pathname
                   (setf (car in-memory) (get-file-stamp pathname)))
                 (cdr in-memory))
                 (error 'missing-component :requires name))
                (t ;; not found: don't keep negative cache, see lp#1335323
                 (unset-asdf-cache-entry `(locate-system ,name))
                 (return-from find-system nil)))))))))

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